1. Field of the Invention
This invention relates to a fluid flow control device and, in a preferred embodiment, to a medical device having a cannula, often a needle, that is insertable into a patient for use in infusing, collecting or extracting fluids. One aspect of the invention relates to a medical device having an actuator that is manipulated to modify a fluid flow path between the cannula and an external fluid source or receptacle following the infusion or extraction. Another aspect of the invention relates to a mechanism that functions as a clamp when attached to a fluid flow line. Another aspect of the invention relates to a mechanism that retracts the cannula inside the device to prevent accidental needlesticks following use and to prevent reuse of the contaminated cannula. Although the subject invention is particularly preferred for use in intravascular (“IV”) applications, it can also be used beneficially, for example, in epidural, intraosseous and intraocular applications, and with any body fluid.
2. Description of Related Art
Intravascular (“IV”) infusion sets are well-known in the art for delivering fluids and/or medications to a patient by means of a cannula connected to tubing. IV infusion devices frequently have attached wings that facilitate handling during insertion of the cannula, help stabilize the device, and can be secured to limit movement of the device during use. Blood collection devices operate on the same principle, but in reverse. Blood is collected from a vein or artery through a cannula that is connected through the body of the device to a blood collection receptacle. Following use of a conventional infusion or fluid collection system, the cannula is contaminated with blood and/or other bodily fluid, and care must be taken to avoid reusing the device and to avoid accidentally sticking either healthcare workers or patients, and thereby spreading blood-borne pathogens. The use of caps or covers that must be replaced over the cannula after withdrawal from a patient are not a satisfactory solution because they increase the risk for an accidental stick, or can become loose and fall off; thereby again exposing the contaminated cannula.
U.S. Pat. No. 5,779,679 to Shaw, entitled “Winged IV Set With Retractable Cannula,” and U.S. Pat. No. 6,210,371 to Shaw, entitled “Winged IV Set,” both disclose an IV infusion set with a retractable cannula. In both of these patents, the retractable cannula is held by a retraction member having a tubing connector on its back end portion that establishes fluid communication between the cannula and an IV tube. The retraction member is held in its non-retracted position against the force of a compressed spring by a pair of releasable latches disposed on opposite sides of the housing. Once the latches are released, the spring forces the retraction member, and consequently the cannula, back into the housing. However, because an IV tube is connected directly to the retraction member, retraction of the cannula causes the IV tube to move rearwardly as well. If the tube is not free to move rearwardly during retraction, the retraction member and the cannula may not be fully retracted.
An infusion and fluid collection device are needed in which the cannula can be retracted without causing or relying upon rearward movement of the connected tubing, and in such manner that the device is rendered non-reusable and that the fluid flow path is interrupted, relocated and sealed off in conjunction with retraction of the cannula.